LAUSR

Abstract Disease in agriculture field is a major issue from food security point of view. In each year different types of diseases (mainly bacterial, fungal and viral) results a huge loss in agricultural production. A wide range of chemical agents are available in the market to reduce the degree of infection in crop plants. However, these are not safe for health and as well as for environment, thus, the demand of bio-control agents are increasing rapidly. In this present investigation, we have demonstrated the antagonictic activity of an agricultural soil bacterium Streptomyces hydrogenans IB310 against both bacterial and fungal phytopathogens ( Agrobacterium tumefaciens , Pseudomonas syringae , Xanthomonas campestris , Botrytis allii, Fusarium oxysporum and Ustilago maydis ). The active antimicrobial compound produced by the bacterium S. hydrogenans IB310 was purified, characterized and identified as actinomycin D. Furthermore, the parameters (glycerol, oat meal and tween 80) responsible for the production of actinomycin D were optimized through Response Surface Methodology (RSM). Highest yield (18.912 mg/L of actinomycin D) was obtained at glycerol 1.949 g/L, oat meal 2.676 g/L and tween 80 0.524 g/L. Due to antagonistic nature against the bacterial and fungal phytopathogens, the strain S. hydrogenans IB310 might be useful as a bio-controlling agent in agricultural field. To the author's best knowledge, it is the first report of actinomycin D production by S. hydrogenans .